@charset "utf-8";

*{
    margin: 0;
    padding: 0;
}

html body{
    width: 100%;
    height: 100%;
    background: #333;
}

h1{
    color: #ffffffb2;
    text-align: center;
    margin-top: 80px;
    font-size: 46px;
}
h2{
    color: #ffffffb2;
    text-align: center;
    margin-top: 20px;
    font-size: 20px;
}

.main-content-box{
    width: 960px;
    height: 600px;
    margin: 50px auto;

    background: rgba(0, 0, 0, 0.246);

    font-size: 16px;
    
}

.main-content-box ul{
    /* 这里设置980px会延伸出20px但是不显示 */
    width: 980px;
}

.main-content-box ul li{
    width: 225px;
    height: 180px;
    float: left;

    margin-right:  20px;

    list-style: none;
}

.main-content-box ul li a{
    display: block;
    width: 225px;
    height: 180px;

    perspective: 300px;
}

.main-content-box ul li a .forward{
    width: 225px;
    height: 180px;

    position: absolute;
    backface-visibility: hidden;
    transition: all 0.5s;
}

.forward:hover{
    transform: rotateY(180deg);
}

.main-content-box ul li a img{
    display: block;
}

.main-content-box ul li a .forward .tips{
    width: 100%;
    height: 25px;
    background: rgba(0, 0, 0, 0.356);

    position: absolute;
    bottom: 0;

    font-size: 17px;
    text-align: center;
    color: #fff;
}





.main-content-box ul li a .back{
    width: 100%;
    height: 180px;
    position: absolute;
    background: url(../img/bg.jpg);
    backface-visibility: hidden;

    transform: rotateY(-180deg);
    transition: all 0.5s;
}

.back:hover{
    transform: rotateY(0deg);
}

.back h3{
    width: 100%;
    height: 50px;

    font-size: 14px;
}
.back p{
    width: 100%;
    height: calc(100% - 50px);

    font-size: 12px;

}

